Answer:
Tetrahedral electron geometry and trigonal pyramidal molecular geometry.
Explanation:
The Lewis structure is shown in Figure 1.
The central N atom has three bonding pairs and one lone pair, for <em>four electron groups</em>.
VSEPR theory predicts a tetrahedral electron geometry with bond angles of 109.5°.
We do not count the lone pair in determining the molecular shape.
The molecular geometry is trigonal pyramidal (see Figure 2).
Answer:
Metal
Element: Calcium
Valency: 2
Explanation:
To find the element, let's use the periodic table. (Look below)
We already went past 3 shells, just need the 2 electrons after it.
Just skip to the 4th row and count 2 to the right
We end up at Calcium.
Calcium is a metal and we're also on the alkaline earth metals column.
Calcium will need to lose 2 electrons to reach stability, so the valency is 2.
Answer:A
Explanation:
The melting points of solids depend in the relative sizes of ions in the ionic lattice. The smaller the relative sizes of the ions, the higher the lattice energy and the stronger the lattice hence higher melting point. Comparing relative ionic sizes, fluoride ion is lesser in size than chloride ion hence NaF has a higher melting point than NaCl.
Gain or lose.
The exchange of electrons in chemical bonding seeks to fulfill the octet rule. There are some exceptions, such as with hydrogen and helium, whose valence shells have a capacity of two electrons.
